ELECTRICAL CONTROL OF PYLORIC MOTILITY

建议用实验研究基本的电生理学。 犬幽门括约肌。幽门的电活动是 很复杂，以前的 细胞外录音或由少数报道的细胞内录音 学习。我们已经开发了横断面制剂 幽门肌层，可精确定位细胞内 微电极，用于表征在任何情况下的电活动 幽门环内或通过厚度的任何水平 肌肉的力量。幽门电信号的完整分析 将执行波形。初步研究表明， 幽门肌肉是由胃窦电活动起搏的 当幽门松开时，幽门的大部分可能是静止的 从远端的胃窦。我们还观察到慢波 当它们在圆形层中传播时振幅衰减 远端穿过幽门环。环状肌的大部分 幽门似乎是一个被动的合胞体，它不 产生或再生慢波活动。这引发了 幽门是如何被激活的，它的活动是如何进行的 与胃蠕动活动相协调。实验以实现 回答这些问题将被执行。它的起源和 电事件的传播机制将是 下定决心。我们还将调查电力行业的监管 幽门内的活动，特别是神经递质 荷尔蒙的影响会影响自发事件和 电事件的传播。最初的假设是 神经调节控制活动的频率 起搏器位置更靠近幽门，但幅度 电事件以及这些事件的传播程度 进入幽门环取决于神经和荷尔蒙 合胞电缆特性和兴奋性的调节 机械装置。我们还将确定两国之间的关系 电气和机械事件。最后，我们将尝试 电生理特征与结构的相关性 测量。我们希望调和电学反应 神经刺激法测定神经密度和神经传导速度 电缆参数对合体结构特性的影响。 这些实验应该为理解 控制幽门运动的基本机制及其解释 幽门在调节胃排空中的作用。

Experiments are proposed to study the basic electrophysiology of canine pyloric sphincter. The electrical activity of the pylorus is complicated and has not been adequately described by previous extracellular recordings or by the few reported intracellular studies. We have developed cross-sectional preparations of the pyloric muscularis which allow precise placement of intracellular microelectrodes to characterize the electrical activity at any point within the pyloric ring or at any level through the thickness of the muscle. A complete analysis of pyloric electrical waveforms will be performed. Preliminary studies have revealed that pyloric muscles are paced by antral electrical activity and that much of the pylorus may be quiescent when it is uncoupled from the distal antrum. We have also observed that slow waves decay in amplitude as they propogate through the circular layer or distally through the pyloric ring. The bulk of the circular muscle of the pylorus appears to be a passive syncytium which does not generate or regenerate slow wave activity. This raises the question of how the pylorus is activated, and how its activity is coordinated with gastric peristaltic activity. Experiments to answer these questions will be performed. The origin and mechanisms of propagation of electrical events will be determined. We will also investigate regulation of electrical activity within the pylorus, specifically how neurotransmitters and hormonal influences affect spontaneous events and the propagation of electrical events. An initial hypothesis is that neural regulation controls the frequency of activity at the pacemaker sites more proximal to the pylorus, but the amplitude of electrical events and the extent of the spread of these events into the pyloric ring depends upon neural and hormonal conditioning of the syncytial cable properties and excitability mechanisms. We will also determine the relationship between electrical and mechanical events. Finally we will attempt to correlate electrophysiological characteristics with structural measurements. We hope to reconcile electrical responses to neural stimulation with measurements of innervation density and cable parameters to structural characteristics of the syncytium. These experiments should provide a basis for understanding the basic mechanisms controlling pyloric motility and help to explain the role of the pylorus in regulating gastric emptying.